Methamphetamine is an addictive stimulant that strongly activates certain systems in the brain.
Meth is a crystal-like powdered substance that sometimes comes in large rock-like chunks.
When the powder flakes off the rock, the shards look like glass,
which is another nickname for meth.
Meth is usually white or yellow, depending on the purity.
Methamphetamine can be taken orally, injected, snorted, or smoked.
Source: National Institute on Drug Abuse
